Tire building apparatus

ABSTRACT

Apparatus for supporting and actuating a tire building drum which comprises a spindle assembly having in the disclosure three telescopically arranged members coaxial with a common longitudinal axis each of which is connectable to actuate particular parts or elements within the drum. Drive trains, designated primary and secondary, each include selectively operable clutches enabling rotation of the spindle assembly both as a synchronously corotatable unit and alternatively for rotating a selected member relative to the other or others. Geared differential units having two inputs connected respectively to different members of the spindle assembly produce rotational outputs proportional to the relative angular displacement between such connected members. The differential outputs can drive a series of cam lugs past a fixed battery of limit switches or a pointer along a scale to measure and to signal to the relative angular displacement of one member relative to the other as well as to control such relative movement. The parts and elements within the drum required to be moved by the members of the spindle assembly are monitored and controlled.

Primary Examiner-Allan D. Herrmann Att0rneyF. W. Brunner et al.

United stateS Patent 1 1111 3,769,856

Casey Nov. 6, 1973 [54] TIRE BUILDING APPARATUS [75] Inventor: WilliamR. Casey, Akron, Ohio [57] ABSTRACT [73] ASSigneB: Th Goodyear Tir &Rubber Apparatus for supporting and actuating a tire building C mp ny,Akron, Ohio drum which comprises a spindle assembly having in the [22]Filed June 28 1972 disclosure three telescopically arranged memberscoaxial with a common longitudinal axis each of which is [21] Appl. No.:266,898 connectable to actuate particular parts or elements within thedrum. Drive trains, designated primary and [52] U Cl 74/675' 156/414192/4 R secondary, each include selectively operable clutches [51] Bzgh7/16 Fl6d 67/02 enabling rotation of the spindle assembly both as a syn-[58] Field ofusearch 74/665 K 665 L chronously corotatable unit andalternatively for rotat- 74/665 M R 48 48 ing a selected member relativeto the other or others. i 415 Geared differential units having twoinputs connected respectively to different members of the spindle assem-[56] References Cited bly produce rotational outputs proportional to therela tive angular displacement between such connected UNITED STATESPATENTS members. The differential outputs can drive a series of Green Xam lugs past a fixed battg y of switches or a I S li 437 5 po nter alonga scale to measure and to signal to the re] c ative angular displacementof one member relative to 1 g fi the other as well as to control suchrelative movement. 3576693 4/1971 pacciarini h: 156,417 The parts andelements within the drum required to be 3:625:072 12 1971 Bobard192/4891 moved y the members of ths Spindle assembly are monitored andcontrolled.

28 Claims, 3 Drawing Figures TIRE BUILDING APPARATUS The foregoingabstract is not to be taken as limiting the invention of thisapplication, and in order to understand the full nature and extent ofthe technical disclosure of this application, reference must be made tothe accompanying drawing and the following detailed description.

This invention relates to tire building apparatus and particularly to adrive apparatus for a tire building drum.

In the following description of a preferred and exemplary embodiment ofthe invention, reference will be made to the attached drawing in which:

FIG. 1 is a schematic plan view of a drive apparatus in accordance withthe invention; and

FIGS. 2 and 3 are schematic sectional views of portions of the apparatusof FIG. 1.

FIG. 1 depicts schematically an apparatus in accordance with theinvention for supporting and actuating a tire building drum 12 a portion12 of which is seen in FIG. 1. The drum is supported for rotation aboutits own longitudinal axis 15. The spindle assembly 20 of the apparatus10 includes a plurality of coaxial members arranged telescopically abouta common longitudinal axis aligned coaxially with the drum. The outermember of the assembly is a tubular spindle 21 of circular cross-sectionwhich is provided with a flange 21' or equivalent means to which thedrum is removably secured. The spindle 21 is carried in suitablebearings (not shown) fixed in the frame housing of apparatus 10. Theframe supports the apparatus 10 in any convenient conventional mannerand is, therefore, not further described nor shown in the drawing.

A tire building drum particularly adapted for use in connection with theapparatus 10 is described in the present applicants application Ser. No.266,885, filed of even date herewith, to which application reference maybe made, the said application being incorporated herein by reference.

The second member is a tubular structure 23, also of circularcross-section, termed herein a'quill, which is mounted in the spindle 21by suitable bearings which permit relative coaxial rotation between thespindle 21 and the quill 23. Formed integrally at the drum end of thequill 23 is a gear 23' suitably adapted to serve as drive coupling meansto engage and to drive a mechanism 23" for raising and lowering thesegments radially of the drum 12. It will be appreciated that this gear23' or its equivalent can as well operate to actuate any independentlyoperable portions of a drum which may be attached to the apparatus 10.The quill 23 extends coaxially through the spindle 21 and outwardlythereof at least sufficiently to accommodate a drive sprocket 23a .fixedcoaxially and corotatably on the quill.

Athird member of the assembly is provided by an inner shaft 25 mountedwithin the quill 23 on suitable bearings which enable relative rotationbetween the inner shaft 25 and the quill. At the drum end of the innershaft 25 is provided a spline 25' which serves as drive coupling meansto engage a corresponding center shaft 25" in the drum l2 and to drive,for example, a screw mechanism (not shown) for moving, in a knownmanner, parts of the drum axially toward and away from each other.Again, it will be appreciated that the inner shaft 25 can be connectedto any such independently operable mechanism within the drum.

15, coaxially through and is supported corotatably in the hollow outputshaft 32 of the reduction gear unit 33 fixed in the frame. The gear unit33 is driven by an electric motor 34 or its equivalent which is coupledto the input shaft 35 of the gear unit. The input shaft 35 carries thebrake disc 36a of the brake 36 which cooperates with the shoes held in abrake caliper 36b affixed to the reduction gear unit.

A sprocket 31a fixed corotatably on the primary shaft 31 is connected bya driving chain 38 to the sprocket 25a mounted on the inner shaft 25. Asprocket 31b mounted rotatably on the primary shaft 31 in coplanaralignment with a sprocket 21a mounted coaxially and corotatably on thespindle 21. The sprockets 21a, 31b are drivably connected by a drivechain 39. A remotely actuable positive jaw clutch 31c is carried by theprimary shaft 31 to permit relative rotation between the sprocket 31band the shaft 31 and alternatively to engage the sprocket 31b with theprimary shaft 31 for positive corotation. The primary drive means justdescribed connects the spindle 21 and the inner shaft 25 for positivesynchronous corotation while the clutch 310 is positively engaged. Byopening or disengaging the clutch, the primary drive means operates torotate only the inner shaft 25 relatively with respect to the spindle21.

During such relative rotation between the inner shaft 25 and the spindle21, the spindle is controlled and held against rotation by brake 41comprising a brake disc 41a mounted corotatably on the spindle 21 and abrake caliper 41b fixed on the frame.

The previously referred to drive means includes also a secondary drivetrain 50 comprising a secondary shaft 51 mounted for rotation about itsown longitudinal axis which is parallel to and spaced radially away fromthe axis 15 of the spindle. A sprocket 514 is coaxially and corotatablyfixed on the shaft 51 in coplanar alignment with and drivingly connectedto a sprocket 21b mounted coaxially and corotatably on the spindle 21 bythe drive chain 52. A sprocket 51b is mounted coaxially and rotatably onthe secondary shaft 51 in coplanar alignment with the sprocket 23a onthe quill 23. A remotely actuable clutch 510 is operable to engage thesprocket 51b with the secondary shaft 5 1 for corotation therewith andto disengage the sprocket 51b to permit its rotation relatively of theshaft 51. The sprocket 51b is connected to the sprocket 23a by a drivechain 53. While the clutch 510 is positively engaged, the spindle 21 andthe quill 23 are positively and synchronously corotatable; opening ordisengaging the clutch 51c permits relative rotation between the quill23 and the spindle 21.

To rotate the quill 23 relatively with respect to the spindle 21 and/orwith respect to the inner shaft 25, a second drive means in the form ofa hydraulic motor 60, orits equivalent, is provided on its output shaft61 with a remotely actuable clutch 62 having a sprocket 63 mountedthereon in coplanar alignment with the chain 53. The chain 53 drivinglyengages each of the sprockets 23a, 51b, and 63. With the clutch 62 openor disengaged, the sprocket 63 free-wheels while the quill 23 is beingrotated by the secondary shaft 51. While the clutch 510 is disengagedand the clutch 62 engaged the sprocket 51b free-wheels about the shaft51 while the quill 23 is driven in rotation relative to the spindle 21and/or to the inner shaft 25 by the motor 60.

In order to control within appropriate limits the relative movement ofthe actuating mechanisms within the drum, it is desired to controlcorrespondingly the relative rotation or relative angular displacementof one member of the assembly 20 relative to the other or others. Tothis end, the apparatus includes a geared differential unit 70, aschematic section view of which is seen in FIG. 2. The differential unit70 has first input means comprising a shaft 71 which is connected inpositive driving relation to the spindle 21 by way of the secondaryshaft 51 for convenience in mechanical arrangement. The secondary shaft51 is positively connected in fixed driving ratio with the spindle 21 bythe chain 52. A sprocket 72 on the secondary shaft 51 is connected witha sprocket 73 by a chain 74. One 75a of a pair of reversing gears 75a,75b is mounted in a frame coaxially and corotatably with the sprocket 73and is in mesh with the other reversing gear 75b which is corotatablyand coaxially mounted on the input shaft 71 of the differential unit 70.The second differential input means comprises an input shaft 76 which isconnected in positive driving relation with the quill 23 by way of thedrive chain 77 which drivingly connects the sprocket 78 with thesprocket 51d mounted on the shaft 51 coaxially and corotatably with thesprocket 51b which, as has been mentioned, is positively connected infixed driving ratio with the sprocket 23a on the quill 23 by the chain53.

The differential unit 70 itself is represented schematically in FIG. 2.The first input shaft 71 extends coaxially of the differential unit andcorotatably carries an input gear 71a. The second input shaft 76extending coaxially of the differential unit carries for corotation thesprocket 78 and the input gear 76a. The differential output meanscomprises the generally cylindrical shell 79 which is mounted onsuitable bearings (not shown) for rotation about its own axis coaxiallyof the differential unit 70. A planet shaft 79a is rotatably fixed inthe shell parallel to and spaced radially from the axis of thedifferential unit. The shaft 79a carries two gears 79b, 79c mountedcoaxially and corotatably thereon and spaced axially thereof. The gear79b is in driving mesh with the first input gear 71a; the gear 790 is indriving mesh with an idler pinion 81 which is fixed rotatably in theshell 79, the pinion 81 being, in turn, in driving mesh with the secondinput gear 76a.

Differential gear units are well understood in the related arts. FIGS. 2and 3 illustrate spur gear differentials but it'will be appreciated thatany differential gear arrangement, for example, a bevel geardifferential, can be used with about equal facility. It will also beunderstood that the schematic showings in FIGS. 2 and 3 are not to scaleand that the gears and pinions within the unit are spaced angularlyabout the rotation axis of the differential unit.

According to well understood principles of differential gear units, theratios of the gears 71a, 79b and of the gears 76a, 81, 790 are selectedsuch that angular displacements or rotations equal in direction andmagnitude of the first and second input shafts 71 and 76 result in zeroangular displacement of the differential shell 79 and that anydifference in direction or in magnitude of angular displacement betweenthe first input means and the second input means results in a rotationor angular displacement output by the differential shell 79. Because theunit is a geared differential, the angular displacement of thedifferential shell 79 will be directly proportional to the algebraicdifference of the angular displacements of the shaft 71 and the shaft76. Thus, the angular displacement of the differential shell 79 will bea direct measure of the relative angular displacement between thespindle 21 and the quill 23.

Further, in accordance with the invention, in order to utilize thedisplacement of the differential shell, a cylindrical sleeve 84 ismounted concentrically on the differential shell 79 and is provided withconventional clamping devices by which the sleeve can be displacedangularly about the shell. The sleeve 84 carries thereon a plurality ofcam lugs 86, the relative positions of which are selectable to representthe relative positions and particularly of the end limits ofdisplacement of the operating mechanism within the drum 12 to beoperated by the relative rotation of the quill 23. To serve asdisplacement sensors which respond to the various angular displacementsof the differential shell 79, a plurality of limit switches 88 are fixedto the frame in such manner as to be engageable by the cam lugs 86 atparticular angular displacements thereof about the differential unitaxis.

In the apparatus 10 a second differential unit [identical parts thereofbeing designated by like numerals distinguished by a prime like thatjust described has its first input shaft 71 connected in positivedriving relation with the spindle 21 by a chain 91 drivingly engagedwith a sprocket 21c corotatably and coaxially fixed on the spindle 21and a sprocket 23 coaxially and corotatably mounted together with afirst reversing gear 95a which meshes with the second reversing gear 95bmounted coaxially on the first input shaft 71 of the differential unit70. The second differential input shaft 76 is connected in positivedriving relation with the shaft 25 by a sprocket 78, mounted coaxiallyand corotatably of the input shaft 76', and the sprocket 25b, thesprockets 78' and 25b being connected by a driving chain 94. Therespective inputs of the differential unit 70' are thus connectedpositively to the spindle 21 and to the inner shaft 25. As in thepreviously described differential unit 70, the differential output meansincludes the differential shell 79. A sprocket 96 mounted coaxially ofand corotatably with the difierential shell 79' is connected by a drivechain 97 to a sprocket 98 mounted coaxially and rotatably on a leadscrew 100. The sprocket 98 is connected for or released from corotationwith the lead screw 100 by a manual clutch 102. The manual clutch can bedisengaged to permit rotation of the lead screw 100 independently andrelatively of the drive 96, 97, 98 and, therefore, of the differentialshell79 for purposes of coordinating the relative rotation of theshaft25 in proper phase with the connecting center screw of the drum 12.

A non-rotating nut 104 is engaged with the lead screw 100 for movementlongitudinally therealong in response to rotationof the screw. It willbe understood that the nut is restrained from rotation by conventionalmeans, not shown. An indicator 106 or pointer fixed on the nutcooperates with a linear scale 108 which is disposed parallel to thelead screw and cooperates with the indicator 106to display an analog ofthe relative axial positions of the axially movable elements within thedrum which are actuated by the inner shaft 25. In order to employ theanalog provided of the angular displacement of the inner shaft 25relative to the spindle 21 and thus of the axial positions of movableelements moved thereby within the drum 12, a plurality of displacementsensors such as the limit switches 110 are fixed at selected intervalsalong the linear scale 108 such that the switches 110 are actuated bycams 112 formed on the nut 104 at preselected intervals of displacementof the nut along the lead screw which displacements are analogous to thedisplacements of the axially movable elements within the drum. Theelectrical or like signals provided by individual limit switches can, aswill be understood, be employed to actuate the clutches, the brakes, andthe drives, as well as for other purposes.

In order to operate further movable elements within the drum 12, airpassage means through the spindle are provided in the apparatus. Theinner shaft 25 is of tubular form which accommodates an air tube 120extending longitudinally therethrough, and between the air tube and theinner wall surface of the inner shaft 25 an annular air passage 122which tube and passage are connected respectively by means of aconventional rotary joint 124 to means for the supply to and releasefrom the drum 12 of compressed air. This feature makes it unnecessary toconnect to the drum and disconnect therefrom temporary air hoses for theoperation of such movements as inflating an elastomeric sleeve on thedrum. The air tube 120 and annular air passage 122 are releasablyconnected to a corresponding annular passage 122' and a tube 120 fixedwithin the drum.

The modes of operation of the apparatus will have become generallyapparent from the foregoing description of the structure. The operationof the tire building drum 12 includes rotation of the drum while axiallyand radially movable elements therein remain relatively fixed inposition within the drum. For this mode of drum operation, the spindleassembly 20 including each of its members, namely, the spindle 21, thequill 23, and the inner shaft 25, are driven in synchronous corotationwithout relative angular displacement between the spindle and the quillor between the spindle and the inner shaft. This mode is accomplished bycooperation of the primary and secondary S0 drive trains, the clutches31c and 510 thereof being in full positive engagement. The brakes 36 and41 are both in released mode and the spindle assembly 20 is driven bythe motor 34 through the reduction gear 33, the primary shaft 31, andthe drive chains 38 and 39. The secondary shaft 51 is driven in fixedratio relation with the spindle 21, and with the clutch 51c positivelyengaged, the quill 23 is therefore likewise positively connected forsynchronous corotation with the assembly 20.

In order to operate one of the plural mechanisms within the drum 12, andin particular by way of example, a plurality of segments which areraised and lowered with respect to the drum axis to expand or tocollapse such drum, the quill 23 is rotated relatively with respect tothe spindle 21 while the latter is maintained nonrotating by applicationof the brake 41. In order to rotate the quill 23 relatively with respectto the spindle 21 and the inner shaft 25, the clutches 31c and 62 areengaged while the clutch 51c is opened or disengaged,

the motor 34 is de-energized and positively stalled by application ofthe motor brake 36 in which mode the inner shaft 25 is also preventedfrom rotating, while the hydraulic motor is energized to drive the chain53 and the quill 23.

The relative rotation between the quill 23 and the spindle 21 produces arelative angular displacement of the differential shell 79 about itsaxis such as to actuate at least one of the limit switches 88. Uponactuation of the limit switch, the relative angular movement of thequill 23 is stopped by disengaging the clutch 62 and engaging the clutch51c.

To provide relative rotation of the inner shaft 25 with respect to thespindle 21, the clutch 62 and clutch 310 are both disengaged and thespindle brake 41 is applied. The motor brake 36 is released and themotor 34 energized to produce power flow from the motor through thereduction gear and primary shaft to the chain 38 by which the innershaft 25 is rotated, the spindle 21 being held nonrotatable by the brake41. In this mode, the input to the differential from the spindle 21 byway of the chain 91 is zero while the second input 76 to thedifferential by way of the chain 94 is rotated in a directioncorresponding tothe relative rotation of the shaft 25 and of the screwwithin the drum which operates to move the end parts of that drum towardor away from each other. 1n the differential shell 79' there results arotational displacement which is an analog of the displacement of theend parts axially of the drum. This angular displacement of thedifferential shell 79' is communicated to the lead screw by way of thechain 97 so as to move the nut 104 linearly along the scale 108 and toengage the nut successively with one or more of the limit switches 110.The actuation of a particular limit switch produces an electrical signaluseful to deenergize the motor 34 and actuate the brake 36 thus stoppingrelative rotation between the inner shaft 25 and the spindle 21 andlocating the axially movable elements of the drum in their preselecteddispositions.

The electrical, hydraulic, and air circuits employed in the apparatusare entirely conventional and not within the scope of the presentinvention, hence require no description.

While certain representative embodiments and details have been shown forthe purpose of illustrating the invention, it will be apparent to thoseskilled in the art that various changes and modifications may be madetherein without departing from the spirit or scope of the invention.

What is claimed is:

I. A tire building drum drive apparatus comprising a rotatable spindleassembly for supporting and actuating said drum, the assembly includingat least three members of circular cross-section disposed telescopicallyabout a common longitudinal axis, each member being rotatable both withand relatively of the other members and each having at its 'drumward endmeans individually drivingly connectable to independently operable partsof said drum, and drive train means operable to rotate at least one pairof said members in synchronous corotation and to rotate at least one ofsaid members relatively with respect to the other said members.

2. Apparatus as claimed in claim 1, including brake means operable tocontrol rotation of at least one of said members during rotation of another of said members relatively of said one thereof.

3. Apparatus as claimed in claim 2, said brake means comprises a brakedisc mounted on said spindle assembly for corotation therewith and acooperating brake shoe mounted on a stationary frame.

4. Apparatus as claimed in claim 1, including differential means havingfirst input means connected in positive driving relation with one ofsaid members, second input means connected in positive driving relationwith an other of said members and differential output means rotatableproportionally to the difference in angular displacement about said axisbetween said one and said other of the respectively associated members.

5. Apparatus as claimed in claim 4, further including means comprising aplurality of cam lugs adjustably fixed on said differential outputmeans, a displacement sensor disposed for engagement with each of saidcam lug at a preselected degree of angular displacement of saiddifferential shell about its own rotation axis.

6. Apparatus as claimed in claim 4, said differential means being arotatable geared differential and said output means being connected byat least one pair of meshing gears to each of said input means.

7. Apparatus as claimed in claim 1, said drive train means including ashaft mounted for rotation parallel to said longitudinal axis, a firstdriving chain drivably connecting a sprocket corotatable with a firstone of said members and a sprocket corotatable with said shaft, a seconddriving chain drivably connecting a sprocket corotatable with a secondone of said members and a sprocket corotatable with said shaft, andmotor means connected to drive said shaft and operable to rotate saidspindle assembly as a synchronously corotating unit.

8. Apparatus as claimed in claim 7, including second drive meansoperable to rotate one of said members relatively of an other thereof.

9. Apparatus as claimed in claim 8, said second drive means comprises ahydraulic motor.

10. Apparatus as claimed in claim 9, including a pair of clutchesoperable to connect one of said members alternatively to said shaft forcorotation with an other of said members and to said second drive meansfor rotation relatively of said other member.

11. Apparatus as claimed in claim 1, said drive train means includingprimary and secondary drive train means each operable to rotate at leastone pair of said members in synchronous corotation and to rotate one ofsaid pair relatively of the other of said pair of members.

12. Apparatus as claimed in claim 11, a pair of clutches operable ineach said drive train means alternatively to connect said members forsynchronous rotation and each clutch to connect respectively one of saidmembers for rotation relatively of an other thereof.

13. A tire building drum drive apparatus comprising:

a rotatable spindle assembly for supporting and actuating said drum, theassembly including a plurality of coaxial members each rotatable withand relatively of the other members and each individually drivinglyconnectable to independently operable parts of said drum,

primary and secondary drive train means each selectably operable torotate at least one pair of said members in synchronous corotation andone of said pair relatively of the other, and

at least one differential means having first input means connected inpositive driving relation with one of said members, second input meansconnected in positive driving relation with an other of said members,and differential output means rotatable proportionally to the differencein angular displacement between said one and said other of therespectively associated members.

14. Apparatus as claimed in claim 13, said drive train means includingbrake means and clutch means cooperable to control rotation of two ofsaid members during rotation relative to said two of an other of saidmembers.

15. Apparatus as claimed in claim 13, including displacement meansassociated with at least one of said differential means to provide adisplacement analog of the relative rotation between the respectivelyassociated other and the one of said members.

16. Apparatus as claimed in claim 15, said differential output meanscomprising a cylindrical shell mounted for rotation about its owncylinder axis, a shaft rotatably fixed in said shell parallel to andspaced radially from said cylinder axis, a pair of gears mountedcorotatably on said shaft and spaced axially thereon, said first inputmeans comprising an input gear in driving mesh with one of said pair ofgears, said second input means comprising a reversing pinion mountedrotatably on said shell in driving mesh with the other of said pair ofgears, and an input gear in driving mesh with said reversing pinion.

17. Apparatus as claimed in claim 16, including positive driving meansfor providing said positive driving relation comprising a chain andsprocket drive positively drivably connecting each said input means witha respectively associated one of said members for fixed ratio drivingrelation therebetween.

18. Apparatus as claimed in claim 15, said displacement means comprisinga plurality of cam lugs adjustably fixed on said differential shell, adisplacement sensor disposed for engagement with each said cam lug at apreselected degree of angular displacement of said differential shellabout its own rotation axis.

19. Apparatus as claimed in claim 15, said displacement means comprisinga lead screw mounted for rotation about its own longitudinal axisproportionally to rotation of said shell, a non-rotatable nut engagedwith said lead screw for linear movement therealong in response torotation of the lead screw, and means fixed on said nut cooperable withmeans fixed in space to display an analog of the relative axialpositions of axially movable elements of said drum.

20. Apparatus as claimed in claim 19, a manually operable clutch forengaging and disengaging said lead screw and said differential shellrespectively in and from driving relationship therebetween.

21. Apparatus as claimed in claim 19, said means fixed on said nutincluding an indicator and said means fixed in space including a linearscale disposed parallel to said lead screw to cooperate with saidindicator to display said analog of the relative axial positions ofaxially movable elements of said drum.

22. Apparatus as claimed in claim 21, a plurality of displacementsensors adjustably disposed along. said screw for detecting movements ofsaid nut to provide actuating signals responsive to selecteddisplacements of said nut.

23. Apparatus as claimed in claim 13, one member of said members being atubular spindle of circular cross-section mounted for rotation about itsown longitudinal axis and having mounting means secured thereon to mountsaid drum for rotation about said axis, an other member of said membersbeing a quill of circular cross-section mounted coaxially in saidspindle for coaxial rotation with and relatively of said spindle andhaving drive coupling means secured thereon to engage and to drive apart of said drum, and a third member of said members being a centershaft mounted coaxially in said quill for coaxial rotation with andrelatively of said quill and said spindle and having drive couplingmeans secured thereon to engage and to drive another part of said drum.

24. Apparatus as claimed in claim 23, including air flow passage meansextending longitudinally of the assembly to connect said drum with meansfor controlling supply to and exhaust from said drum of compressed air.

25. Apparatus as claimed in claim 13, said first input means of said atleast one differential means being connected in positive drivingrelation with said spindle, said second input means being connected inpositive driving relation with said quill, and differential output meansrotatable proportionally to the relative angular displacement betweenthe spindle and the quill, and second differential means having firstinput means connected in positive driving relation with said spindle,second input means connected in positive driving relation with saidcenter shaft, and differential output means rotatable proportionally tothe relative angular displacement between the spindle and the centershaft.

26. Apparatus as claimed in claim 25, including displacement meansassociated with each of said differential means to provide adisplacement analog of the relative rotation respectively between thespindle and the quill, and the spindle and the center shaft.

27. Apparatus as claimed in claim 26, said displacement means associatedwith said quill comprising a plurality of cam lugs adjustably fixed onsaid differential shell, a displacement sensor disposed for engagementwith each said cam lug at a preselected degree of angular displacementof said differential shell about its own rotation axis.

28. Apparatus as claimed in claim 26, said displacement means associatedwith said center shaft comprising a lead screw mounted for rotationabout its own longitudinal axis proportionally to rotation of saidshell, a non-rotatable nut engaged with said lead screw for linearmovement therealong in response to rotation of the lead screw, and meansfixed on said nut cooperable with means fixed in space to display ananalog of the relative axial positions of axially movable elements ofsaid drum.

1. A tire building drum drive apparatus comprising a rotatable spindleassembly for supporting and actuating said drum, the assembly includingat least three members of circular crosssection disposed telescopicallyabout a common longitudinal axis, each member being rotatable both withand relatively of the other members and each having at its drumward endmeans individually drivingly connectable to independently operable partsof said drum, and drive train means operable to rotate at least one pairof said members in synchronous corotation and to rotate at least one ofsaid members relatively with respect to the other said members. 2.Apparatus as claimed in claim 1, including brake means operable tocontrol rotation of at least one of said members during rotation of another of said members relatively of said one thereof.
 3. Apparatus asclaimed in claim 2, said brake means comprises a brake disc mounted onsaid spindle assembly for corotation therewith and a cooperating brakeshoe mounted on a stationary frame.
 4. Apparatus as claimed in claim 1,including differential means having first input means connected inpositive driving relation with one of said members, second input meansconnected in positive driving relation with an other of said members anddifferential output means rotatable proportionally to the difference inangular displacement about said axis between said one and said other ofthe respectively associated members.
 5. Apparatus as claimed in claim 4,further including means comprising a plurality of cam lugs adjustablyfixEd on said differential output means, a displacement sensor disposedfor engagement with each of said cam lug at a preselected degree ofangular displacement of said differential shell about its own rotationaxis.
 6. Apparatus as claimed in claim 4, said differential means beinga rotatable geared differential and said output means being connected byat least one pair of meshing gears to each of said input means. 7.Apparatus as claimed in claim 1, said drive train means including ashaft mounted for rotation parallel to said longitudinal axis, a firstdriving chain drivably connecting a sprocket corotatable with a firstone of said members and a sprocket corotatable with said shaft, a seconddriving chain drivably connecting a sprocket corotatable with a secondone of said members and a sprocket corotatable with said shaft, andmotor means connected to drive said shaft and operable to rotate saidspindle assembly as a synchronously corotating unit.
 8. Apparatus asclaimed in claim 7, including second drive means operable to rotate oneof said members relatively of an other thereof.
 9. Apparatus as claimedin claim 8, said second drive means comprises a hydraulic motor. 10.Apparatus as claimed in claim 9, including a pair of clutches operableto connect one of said members alternatively to said shaft forcorotation with an other of said members and to said second drive meansfor rotation relatively of said other member.
 11. Apparatus as claimedin claim 1, said drive train means including primary and secondary drivetrain means each operable to rotate at least one pair of said members insynchronous corotation and to rotate one of said pair relatively of theother of said pair of members.
 12. Apparatus as claimed in claim 11, apair of clutches operable in each said drive train means alternativelyto connect said members for synchronous rotation and each clutch toconnect respectively one of said members for rotation relatively of another thereof.
 13. A tire building drum drive apparatus comprising: arotatable spindle assembly for supporting and actuating said drum, theassembly including a plurality of coaxial members each rotatable withand relatively of the other members and each individually drivinglyconnectable to independently operable parts of said drum, primary andsecondary drive train means each selectably operable to rotate at leastone pair of said members in synchronous corotation and one of said pairrelatively of the other, and at least one differential means havingfirst input means connected in positive driving relation with one ofsaid members, second input means connected in positive driving relationwith an other of said members, and differential output means rotatableproportionally to the difference in angular displacement between saidone and said other of the respectively associated members.
 14. Apparatusas claimed in claim 13, said drive train means including brake means andclutch means cooperable to control rotation of two of said membersduring rotation relative to said two of an other of said members. 15.Apparatus as claimed in claim 13, including displacement meansassociated with at least one of said differential means to provide adisplacement analog of the relative rotation between the respectivelyassociated other and the one of said members.
 16. Apparatus as claimedin claim 15, said differential output means comprising a cylindricalshell mounted for rotation about its own cylinder axis, a shaftrotatably fixed in said shell parallel to and spaced radially from saidcylinder axis, a pair of gears mounted corotatably on said shaft andspaced axially thereon, said first input means comprising an input gearin driving mesh with one of said pair of gears, said second input meanscomprising a reversing pinion mounted rotatably on said shell in drivingmesh with the other of said pair of gears, and an input gear in drivingmesh with said reversing pinion.
 17. Apparatus as claimed in claim 16,incLuding positive driving means for providing said positive drivingrelation comprising a chain and sprocket drive positively drivablyconnecting each said input means with a respectively associated one ofsaid members for fixed ratio driving relation therebetween. 18.Apparatus as claimed in claim 15, said displacement means comprising aplurality of cam lugs adjustably fixed on said differential shell, adisplacement sensor disposed for engagement with each said cam lug at apreselected degree of angular displacement of said differential shellabout its own rotation axis.
 19. Apparatus as claimed in claim 15, saiddisplacement means comprising a lead screw mounted for rotation aboutits own longitudinal axis proportionally to rotation of said shell, anon-rotatable nut engaged with said lead screw for linear movementtherealong in response to rotation of the lead screw, and means fixed onsaid nut cooperable with means fixed in space to display an analog ofthe relative axial positions of axially movable elements of said drum.20. Apparatus as claimed in claim 19, a manually operable clutch forengaging and disengaging said lead screw and said differential shellrespectively in and from driving relationship therebetween. 21.Apparatus as claimed in claim 19, said means fixed on said nut includingan indicator and said means fixed in space including a linear scaledisposed parallel to said lead screw to cooperate with said indicator todisplay said analog of the relative axial positions of axially movableelements of said drum.
 22. Apparatus as claimed in claim 21, a pluralityof displacement sensors adjustably disposed along said screw fordetecting movements of said nut to provide actuating signals responsiveto selected displacements of said nut.
 23. Apparatus as claimed in claim13, one member of said members being a tubular spindle of circularcross-section mounted for rotation about its own longitudinal axis andhaving mounting means secured thereon to mount said drum for rotationabout said axis, an other member of said members being a quill ofcircular cross-section mounted coaxially in said spindle for coaxialrotation with and relatively of said spindle and having drive couplingmeans secured thereon to engage and to drive a part of said drum, and athird member of said members being a center shaft mounted coaxially insaid quill for coaxial rotation with and relatively of said quill andsaid spindle and having drive coupling means secured thereon to engageand to drive another part of said drum.
 24. Apparatus as claimed inclaim 23, including air flow passage means extending longitudinally ofthe assembly to connect said drum with means for controlling supply toand exhaust from said drum of compressed air.
 25. Apparatus as claimedin claim 13, said first input means of said at least one differentialmeans being connected in positive driving relation with said spindle,said second input means being connected in positive driving relationwith said quill, and differential output means rotatable proportionallyto the relative angular displacement between the spindle and the quill,and second differential means having first input means connected inpositive driving relation with said spindle, second input meansconnected in positive driving relation with said center shaft, anddifferential output means rotatable proportionally to the relativeangular displacement between the spindle and the center shaft. 26.Apparatus as claimed in claim 25, including displacement meansassociated with each of said differential means to provide adisplacement analog of the relative rotation respectively between thespindle and the quill, and the spindle and the center shaft. 27.Apparatus as claimed in claim 26, said displacement means associatedwith said quill comprising a plurality of cam lugs adjustably fixed onsaid differential shell, a displacement sensor disposed for engagementwith each said cam lug at a preselected degree of angular displacementOf said differential shell about its own rotation axis.
 28. Apparatus asclaimed in claim 26, said displacement means associated with said centershaft comprising a lead screw mounted for rotation about its ownlongitudinal axis proportionally to rotation of said shell, anon-rotatable nut engaged with said lead screw for linear movementtherealong in response to rotation of the lead screw, and means fixed onsaid nut cooperable with means fixed in space to display an analog ofthe relative axial positions of axially movable elements of said drum.